pKa Prediction for Organic Acids and Bases
pKa Prediction for Organic Acids and Bases

Author: D. Perrin

Publisher: Springer Science & Business Media

Published: 2013-06-29

Total Pages: 154

ISBN-13: 9400958838

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Many chemists and biochemists require to know the ionization constants of organic acids and bases. This is evident from the Science Citation Index which lists The Determination of Ionization Constants by A. Albert and E. P. Serjeant (1971) as one of the most widely quoted books in the chemical literature. Although, ultimately, there is no satisfactory alternative to experimental measurement, it is not always convenient or practicable to make the necessary measure ments and calculations. Moreover, the massive pK. compilations currently available provide values for only a small fraction of known or possible acids or bases. For example, the compilations listed in Section 1. 3 give pK. data for some 6 000--8 000 acids, whereas if the conservative estimate is made that there are one hundred different substituent groups available to substitute in the benzene ring of benzoic acid, approximately five million tri-substituted benzoic acids are theoretically possible. Thus we have long felt that it is useful to consider methods by which a pK. value might be predicted as an interim value to within several tenths of a pH unit using arguments based on linear free energy relationships, by analogy, by extrapolation, by interpolation from existing data, or in some other way. This degree of precision may be adequate for many purposes such as the recording of spectra of pure species (as anion, neutral molecule or cation), for selection of conditions favourable to solvent extraction, and for the interpretation of pH-profiles for organic reactions.

Computational Approaches for the Prediction of pKa Values
Computational Approaches for the Prediction of pKa Values

Author: George C. Shields

Publisher: CRC Press

Published: 2013-12-07

Total Pages: 178

ISBN-13: 1466508787

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The pKa of a compound describes its acidity or basicity and, therefore, is one of its most important properties. Its value determines what form of the compound—positive ion, negative ion, or neutral species—will be present under different circumstances. This is crucial to the action and detection of the compound as a drug, pollutant, or other active chemical agent. In many cases it is desirable to predict pKa values prior to synthesizing a compound, and enough is now known about the salient features that influence a molecule’s acidity to make these predictions. Computational Approaches for the Prediction of pKa Values describes the insights that have been gained on the intrinsic and extrinsic features that influence a molecule’s acidity and discusses the computational methods developed to estimate acidity from a compound’s molecular structure. The authors examine the strengths and weaknesses of the theoretical techniques and show how they have been used to obtain information about the acidities of different classes of chemical compounds. The book presents theoretical methods for both general and more specific applications, covering methods for various acids in aqueous solutions—including oxyacids and related compounds, nitrogen acids, inorganic acids, and excited-state acids—as well as acids in nonaqueous solvents. It also considers temperature effects, isotope effects, and other important factors that influence pKa. This book provides a resource for predicting pKa values and understanding the bases for these determinations, which can be helpful in designing better chemicals for future uses.

Essential Organic Chemistry, Global Edition
Essential Organic Chemistry, Global Edition

Author: Paula Yurkanis Bruice

Publisher:

Published: 2015-06-04

Total Pages: 704

ISBN-13: 9781292089034

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NOTE You are purchasing a standalone product; MasteringChemistry does not come packaged with this content. If you would like to purchase both the physical text and MasteringChemistry search for 032196747X / 9780321967473 Essential Organic Chemistry 3/e Plus MasteringChemistry with eText -- Access Card Package: The access card package consists of: 0321937716 / 9780321937711 Essential Organic Chemistry 3/e0133857972 / 9780133857979 MasteringChemistry with PearsonKey Benefits: MasteringChemistry should only be purchased when required by an instructor." For one-term Courses in Organic Chemistry. " A comprehensive, problem-solving approach for the brief Organic Chemistry course. Modern and thorough revisions to the streamlined, " Essential Organic Chemistry f"ocus on developing students' problem solving and analytical reasoning skills throughout organic chemistry. Organized around reaction similarities and rich with contemporary biochemical connections, Bruice's Third Edition discourages memorization and encourages students to be mindful of the fundamental reasoning behind organic reactivity: electrophiles react with nucleophiles. Developed to support a diverse student audience studying organic chemistry for the first and only time, Essentials fosters an understanding of the principles of organic structure and reaction mechanisms, encourages skill development through new Tutorial Spreads and emphasizes bioorganic processes. Contemporary and rigorous, Essentials addresses the skills needed for the 2015 MCAT and serves both pre-med and biology majors. Also Available with MasteringChemistry(R) This title is also available with MasteringChemistry - the leading online homework, tutorial, and assessment system, designed to improve results by engaging students before, during, and after class with powerful content. Instructors ensure students arrive ready to learn by assigning educationally effective content before class, and encourage critical thinking and retention with in-class resources such as Learning Catalytics(TM). Students can further master concepts after class through traditional and adaptive homework assignments that provide hints and answer-specific feedback. The Mastering gradebook records scores for all automatically graded assignments in one place, while diagnostic tools give instructors access to rich data to assess student understanding and misconceptions. MasteringChemistry brings learning full circle by continuously adapting to each student and making learning more personal than ever--before, during, and after class.

Physical Methods in Heterocyclic Chemistry
Physical Methods in Heterocyclic Chemistry

Author: A. R. Katritzky

Publisher: Elsevier

Published: 2013-10-22

Total Pages: 497

ISBN-13: 1483273199

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Physical Methods in Heterocyclic Chemistry, Volume IV, discusses the application of physical methods to organic chemistry, and in particular to heterocyclic chemistry. Since the publication in 1963 of the first two volumes of this treatise, the application of physical methods to organic chemistry, and in particular to heterocyclic chemistry, has proceeded apace. The importance of physical methods to structure determination and to the understanding of inter- and intramolecular interactions has increased no less than the flood of new work. Heterocyclic chemists are thus faced with the necessity of having more to comprehend for the efficient execution of their own work. The present volume includes chapters on electric dipole moments and heteroaromatic reactivity, which originally appeared in Volume I, and chapters on nuclear quadrupole resonance, nuclear magnetic resonance, and infrared spectra, which originally formed part of Volume II. Also included is one new topic: dielectric absorption.

Molecular Interaction Fields
Molecular Interaction Fields

Author: Gabriele Cruciani

Publisher: John Wiley & Sons

Published: 2006-05-12

Total Pages: 328

ISBN-13: 3527607137

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This unique reference source, edited by the world's most respected expert on molecular interaction field software, covers all relevant principles of the GRID force field and its applications in medicinal chemistry. Entire chapters on 3D-QSAR, pharmacophore searches, docking studies, metabolism predictions and protein selectivity studies, among others, offer a concise overview of this emerging field. As an added bonus, this handbook includes a CD-ROM with the latest commercial versions of the GRID program and related software.

Free Energy Relationships in Organic and Bio-Organic Chemistry
Free Energy Relationships in Organic and Bio-Organic Chemistry

Author: Andrew Williams

Publisher: Royal Society of Chemistry

Published: 2019-05-16

Total Pages: 316

ISBN-13: 1788018303

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Introducing the application of free energy correlations to elucidating the mechanisms of organic and bio-organic reactions, this book provides a new and illuminating way of approaching a potentially complex topic. The idea of how free energy correlations derive from polar substituent change is introduced, and common pitfalls encountered in the application of free energy relationships are described, along with the use of these anomalies in mechanistic studies. The concept of effective charge is described in detail, with examples of its application. Throughout, worked answers are provided for the problems posed. Databases of parameters, an extensive bibliography and comprehensive lists of further reading are also included. The text provides an invaluable source of information to senior undergraduates, postgraduates and to industrial researchers with an interest in mechanistic studies. It is the first such book in more than thirty years.

Purification of Laboratory Chemicals
Purification of Laboratory Chemicals

Author: W.L.F. Armarego

Publisher: Elsevier

Published: 2003-03-07

Total Pages: 627

ISBN-13: 0080515460

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Now in its fifth edition, the book has been updated to include more detailed descriptions of new or more commonly used techniques since the last edition as well as remove those that are no longer used, procedures which have been developed recently, ionization constants (pKa values) and also more detail about the trivial names of compounds.In addition to having two general chapters on purification procedures, this book provides details of the physical properties and purification procedures, taken from literature, of a very extensive number of organic, inorganic and biochemical compounds which are commercially available. This is the only complete source that covers the purification of laboratory chemicals that are commercially available in this manner and format. * Complete update of this valuable, well-known reference* Provides purification procedures of commercially available chemicals and biochemicals* Includes an extremely useful compilation of ionisation constants

Absorption and Drug Development
Absorption and Drug Development

Author: Alex Avdeef

Publisher: John Wiley & Sons

Published: 2003-09-19

Total Pages: 313

ISBN-13: 0471450251

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Many times drugs work fine when tested outside the body, but when they are tested in the body they fail. One of the major reasons a drug fails is that it cannot be absorb by the body in a way to have the effect it was intended to have. Permeability, Solubility, Dissolution, and Charged State of Ionizable Molecules: Helps drug discovery professionals to eliminate poorly absorbable molecules early in the drug discovery process, which can save drug companies millions of dollars. Extensive tabulations, in appendix format, of properties and structures of about 200 standard drug molecules.